• Proceedings of the Korea Information Processing Society Conference
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• 2006.11a
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• pp.231-234
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• 2006

H.264 코딩시 Intra 모드는 다양한 모드 즉, 매크로블록(MB) 당 16개의 $4{\times}4$ 블록 각각에 대한 9가지의 $4{\times}4$ 모드와 4가지의 $16{\times}16$ 모드의 오류 값을 계산하여 최상의 모드를 선택하게 된다. 이와 같은 픽셀 기반의 예측 기법을 DCT 기반의 MPEG-2/H.264 트랜스코더에 적용할 경우 DCT 변환의 특성으로 인하여 모드 예측을 위한 계산량이 높아지는 단점이 있다. 본 논문에서는 이러한 문제점을 해결하기 위해 MPEG2 DCT를 H.264의 정수형 DCT로 변환한 후, DCT 계수의 특징을 이용하여 Intra 모드를 결정하는 기법을 제안한다. 이때, 계수의 특징이 모호하여 모드를 결정하기 어려운 경우는 몇 가지 모드를 선택하여 오류 값을 계산하여 모드를 결정한다. 현재 정밀한 실험은 진행 중이며, 여러 동영상의 첫 Intra 프레임에 대한 실험을 수행한 결과 MB의 모드 결정의 정확도는 프레임 내 이미지의 특징에 영향을 많이 받았다. 예를 들면 Mobile과 같이 프레임 내의 픽셀 간 에지가 많이 존재하는 프레임은 추가적인 모드 결정을 사용하지 않아도 93%정도의 정확도를 보였으며 Akiyo, Foreman과 같이 이웃한 픽셀간 유사도가 상대적으로 높은 경우는 약 80% 정도의 순수 정확성을 보였다. 그러나 모드 판단이 모호한 경우의 모드도 결정한다면 90%이상의 정확도를 보일 것으로 예상된다. 향후 이미지의 특성에 따라 모드를 결정하는 값을 유동적으로 설정하는 기법을 연구하여 정확도를 높이는 연구를 수행하도록 하겠다.

• Journal of the Korea Institute of Building Construction
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• v.14 no.4
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• pp.292-300
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• 2014

The construction progress control is very important because there are many unexpected factors affecting time schedule delay and cost overruns. A complicated measure including item quantity and inherent time and costs is used to monitor the progress. Another element to be considered is a productivity, which is cost effectiveness because productivity is primarily measured by the costs. Productivity is stated as constant in-place value divided by inputs such as worker-hour. The main purpose of this paper is to analyze the productivity of structural formwork using a 3D BIM. In order to achieve the research objective, an integrated model of a BIM with a daily foreman's report is developed. The quantities being extracted from a 3D model and information are integrated with manpower utilized. The developed model is applied to a case project to measure and analyze the productivity in terms of individual building and work crew team. The results are discussed and further research topics will be addressed.

• Fire Science and Engineering
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• v.32 no.4
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• pp.95-102
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• 2018

The purpose of this study is to discuss an academic concept transition of volunteer firefighting after implementation of the "Volunteer Fire Brigade Establishment & Operation Act". For that, the definition, function, and support of member for the volunteer fire brigade and the quasi-public organization were compared and analyzed using laws and its implementing ordinances, local ordinances, references, etc. In results, we can consider the definition of the volunteer fire brigade in relation to that of the quasi-public organization. In addition, it showed that the volunteer fire brigade have the function of the sub-administrative organization in the quasi-public organization. The support of volunteer firefighting was very similar to that of the village foreman as example of the sub-administrative organization. In conclusion, an academic concept of the volunteer firefighting was translated from the general volunteer organization to the sub-administrative organization in the quasi-public organization. The result in this paper is expected to serve as a basis for the research of the volunteer fire department in Korea.

• Journal of the Korea Institute of Building Construction
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• v.21 no.3
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• pp.249-256
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• 2021

Fatal accidents in the construction industry account for a higher proportion than other industries, and in particular, the collapse accident of formwork is likely to lead to a serious accident like death. This study aim to derive the importance ranking of formwork collapse factors using AHP technique for preventing fatal accident. The AHP survey was conducted on field construction engineers, construction project managers, safety managers, and formwork specialist foreman with 10 years on site experience. The results of AHP analysis is that the most importance factor of formwork collapse accident is 'non-compliance with the formwork shoring assembly drawing'. Next it is important in the order of 'poor installation of formwork shoring and accessories', 'formwork shoring is not installed vertically', 'non-compliance with the concrete curing period of the formwork shoring', 'safety supervisor not designated and negligent'. It is necessary to preferentially and intensively manage the high importance factors presented as a result of this research for reducing formwork collapse accident. In addition, it will contribute to reducing construction safety accidents if the factors of the formwork collapse accident suggested in this research are included in the formwork inspection check list and checked step by step in formwork construction.